Tiny, thornlike trichomes on leaves are a common plant adaptation to ward off insects. Those trichomes develop very early on, as outgrowths of a seedling’s epidermal cells. Biologists have observed, however, that many mature plants develop more leaf trichomes after the fact, as a response to insect damage. Researchers at the University of Chicago decided to study this phenomenon, and specifically wanted to determine the effects, if any, of jasmonate, salicylic acid, and gibberellin in stimulating trichome development. Keeping in mind that plant hormones often interact, how many separate experiments, at a minimum, would the research team have had to carry out to obtain useful initial data? Do you suppose they used mutant plants for some or all of the tests? Why or why not?
